갑상선 초음파에서 computer-aided diagnosis system을 이용한 갑상선 결절의 평가: 영상의학과 의사의 경험에 따른 전향적 비열등성 연구

Abstract

Purpose: To determine whether a CAD system for the evaluation of thyroid nodules is non-inferior to radiologists with different levels of experience. Materials and Methods: Institutional review board approval and informed consent were obtained for this prospective non-inferiority study. Patients with thyroid nodules with a decisive diagnosis, whether benign or malignant, were consecutively enrolled from November 2017 to September 2018. Three radiologists with different levels of experience (1 month, 4 year, and 7 years) in thyroid ultrasound reviewed the thyroid ultrasound with and without the use of a CAD system. Statistical analyses included non-inferiority testing of the diagnostic accuracy for malignant thyroid nodules between the CAD system and the three radiologists with a non-inferiority margin of 10%, comparison of the diagnostic performance, and the added value of the CAD system on the radiologists. Results: A total of 197 patients (165 patients with a benign nodule [84.8%] and 25 patients with a malignant nodule [15.2%]) were included in the study cohort. The diagnostic accuracy of the CAD system [88.4%, 95% confidence interval (CI) = 82.65–92.53] was non-inferior to that of the radiologists with less experience (1 month and 4 year) on thyroid US (83.03, 95% CI = 76.52–88.02; P < 0.001), whereas it was inferior to that of the experienced radiologist (7 years) (95.76%, 95% CI = 91.37–97.96; P = 0.138). The sensitivity and negative predictive value of the CAD system were significantly higher than those of the less-experienced radiologists, whereas no significant difference was found with the experienced radiologist. A conjunctive combination of grayscale US and the CAD system significantly improved sensitivity and negative predictive value, although specificity and positive predictive value deteriorated for the less-experienced radiologists. Conclusion: The CAD system may offer support for decision-making in the diagnosis of malignant thyroid nodules for operators who have less experience in thyroid US.